The present invention relates a solid state imaging apparatus which includes a plurality of pixels two-dimensionally arranged in the vertical direction and the horizontal direction, every two vertically or horizontally adjacent ones of the plurality of pixels including color filters of different colors, respectively.
(First Known Example)
In recent years, as an exemplary solid state imaging apparatus, for example, a apparatus shown in FIG. 10 has been known (see Japanese Patent Publication No. 2001-292453).
Hereinafter, the known solid state imaging apparatus described in the above-described publication will be described with reference to FIG. 10.
In FIG. 10, the reference numeral 201 denotes a set of a plurality of pixels arranged in a matrix, the reference numeral 202 denotes a pixel unit consisting of four pixels arranged in two rows and two columns, the reference numeral 203 denotes a first pixel mixture unit consisting of a plurality of pixels which form a first pixel mixture area, the reference numeral 204 denotes a second pixel mixture unit consisting of a plurality of pixels which form a second pixel mixture area, and the reference numeral 205 denotes a third pixel mixture unit consisting of a plurality of pixels which form a third pixel mixture area. Moreover, in FIG. 10, the reference numeral 206 denotes a vertical shift register and the reference numeral 207 denotes a path of a signal output from the vertical shift register 206.
Hereinafter, for the purpose of simplification, the operations of two types of pixels of the four pixels constituting the pixel unit 202 which are represented by shadowed square and circle, respectively, will be described.
In the first pixel mixture unit 203, nine pixels represented by shadowed squares are pixels of which the charge signals are to be mixed. When sequential scanning of the vertical shift register 206 has been performed from the 1st row to the 5th row, charge signals of the nine pixels which are to be pixel mixture targets and are represented by the shadowed squares are obtained. Thereafter, pixels are mixed.
At this time, scanning of the vertical shift register 206 has performed up to the 5th row, and signals of three pixels which constitute the second pixel mixture unit 204 and are represented by shadowed circles have been output. Therefore, it is necessary to hold these signals.
Next, when scanning of the vertical shift register 206 performs from the sixth row to the 8th row, pixel mixture is performed to signals of six pixels which are to be pixel mixture targets located at the 6th and 8th rows and are represented by shadowed circles and the three pixels of the 4th row which have been already held. Then, signals of three pixels which are located at the 7th, constitute the third pixel mixture unit 205 and are represented by shadowed squares are held.
(Second Known Example)
Hereinafter, as a second known example, a solid state imaging apparatus using a driving circuit described in Japanese Unexamined Patent Publication No. 2002-314882 will be described with reference to FIG. 11.
As shown in FIG. 11, the solid state imaging apparatus includes an imaging section 301 having a plurality of pixel sections 3011, 3012, 3013, . . . which are arranged in a matrix, a driving circuit 303 for supplying a column selection signal to a column selection signal line 302, and a driving circuit 307 for supplying a row selection signal to a row selection signal line 308.
FIG. 12 is a diagram illustrating a block diagram of the driving circuit 303. As shown in FIG. 12, when a scan pulse 309 is input to a driving register 3031 and, furthermore, a clock pulse 305 is applied thereto, an output signal 310 of the driving register 3031 is input to the selection circuit 3041. The selection circuit 3041 outputs an output of the driving register 3031 to a driving register 3032 or a driving register 3033 according to the selection signal 306. Specifically, when the control signal 306 indicating sequential scanning is input, the driving registers sequentially output respective column selection signals, for example, in the manner in which the driving registers 3031, 3032, 3033, 3034, . . . output respective column selection in this order. Thus, pixels are scanned through sequential scanning, for example, in the manner in which the pixel sections 3011, 3012, 3013, 3014, . . . are scanned in this order.
Moreover, when a control signal 306 indicating interlaced scanning, every second driving register outputs a column selection signal to the column selection signal line 302, for example, in the manner in which the driving register 3031, 3033, 3035, . . . output respective column selection signals in this order. Thus, pixels are scanned through interlaced scanning, for example, in the manner in which the pixel sections 3011, 3013, 3015, . . . are scanned in this order.
By the way, in the solid state imaging apparatus of the first known example, an operation in which signals of pixels in a row of a pixel mixture unit (a basic unit of a pixel mixture area) in a subsequent stage is not immediately output but held is required in scanning in the vertical direction.
Thus, in the known solid state imaging apparatus, in the process of scanning a solid stage imaging element in the vertical direction, an operation of holding signals of pixels in a row of a pixel mixture unit constituting a subsequent stage is required. Therefore, a first problem arises in which the operation and circuit configuration of the solid state imaging apparatus becomes complicated.
Moreover, for recent solid state imaging apparatuses, there have been increased demands for use of a solid state imaging apparatus in dealing with not only a static image but also a moving image. For example, in a digital camera, a solid state imaging apparatus loaded in a digital camera outputs a moving image as a monitor image to be displayed on a liquid crystal display panel. However, although the solid state imaging apparatus of the second known example can perform interlaced scanning to deal with a moving image, pixels are thinned out due to the interlaced scanning, so that part of pixel information is omitted. Therefore, a second problem arises in which an unnatural color appears in a display image, i.e., so-called false color occurs, resulting in poor image quality.